An external condition control device based on measurement of brain functions (also called “biological control device”) is operated by opto-biological measurement method and biological input device, and it is applied for operation of alarm device to give warning on physical conditions of a subject on test such as sleeping or decline of attentiveness and for the control of various types of devices without using button, mouse or handle for the control of the devices in the external condition to match the state of consciousness and unconsciousness of the subject, judgment of skillfulness in rehabilitation, the result of learning or displaying of sensing and thinking of the subjects including infants, adults or animals or for detection of lie.
In the past, various types of input devices such as button, keyboard or mouse have been used to operate information processing devices, video game devices, household electric appliances, audio-visual devices, transport devices, etc. However, the input devices operated by manual operation of a human operator may temporarily hinder the attention concentrated on another input operation or may decrease the feeling of the subject (i.e. an operator of a device or a player of video game) as if he or she were actually present at the site. Also, difficulties may arise when a physically handicapped person operates the device. In this respect, attempts have been made to control the device by using information directly obtained from the brain of the subject (i.e. the user).
As for the means for obtaining control information as described above by directly measuring the brain functions, studies have been performed to directly pick up electric signal by placing electrode into brain of the subject. However, in the measurement method, by which it is necessary to embed and bury an implant device by putting it into human body (invasive method), there is always a possibility to cause side effects (adverse effects). On the other hand, as a noninvasive method, i.e. as a measurement method not using the means such as needle or surgical knife to put into human body, various methods are known, e.g. positron emission tomography (PET), functional magnetic resonance imaging (fMRI), electroencephalography, etc.
The Patent Document 1 discloses a device, by which control information from brain of a subject based on brain wave is directly inputted into a controlled device. In the device disclosed in the Patent Document 1, the data of brain wave is directly inputted into an information processing device in a manner similar to the case where measurement is made by means of electrocardiogram, and it is attempted to control a computer—in particular, a video game device. By the direct input device to input the data from brain to a controlled device, even a patient with difficulties in motor functions can control the external device, and this may be helpful in promoting the return of the physically handicapped persons to direct participation in social activities.
Further, in addition to the techniques as described above, a new technique has been introduced by using near infrared spectroscopy. According to this method, the changes of a blood amount in a cerebral cortex associated with brain activities are measured at a multiple of points on the head of the subject, and the changes of blood amount are displayed (optical topography). This method has been used in practical application, and it is published in the Non-Patent Document 2.
As the techniques to disclose the background art in this field, the techniques disclosed in the Patent Documents 3 to 6 and the Non-Patent Documents 1 to 3 are known in addition to the Patent Documents 1 and 2 as given above. The details of the disclosures in these documents will be described later as necessary in connection with the problems to be solved by the present invention, the means for solving the problems, and in the description of the embodiment of the invention.                [Patent Document 1] JP-A-7-124331        [Patent Document 2] Japanese Patent No. 3543453        [Patent Document 3] JP-A-9-149894        [Patent Document 4] JP-A-2000-172407        [Patent Document 5] JP-A-2002-119511        [Patent Document 6] JP-A-2005-13464 (Opto-biological measuring device)        [Non-Patent Document 1] Maki, A. et al., (1995): “Spatial and temporal analysis of human motor activity using noninvasive NIR topography”; Medical Physics 22; 1997-20.        [Non-Patent Document 2] “http://www.hitachi. co.jp/New/cnews/month/2005/09/0926.html”; A product marketed in the name of “Kokoro Gatari” (Mind-Talker); A yes/no judging device for the patients of ALS, who cannot move own body”        [Non-Patent Document 3] Vapnik, V. N.: “The Nature of Statistical Learning Theory, 2nd Ed.”, Springer; 2000.        